diff --git a/src/python/m5/main.py b/src/python/m5/main.py
index 8a259f3..08b1464 100644
--- a/src/python/m5/main.py
+++ b/src/python/m5/main.py
@@ -193,6 +193,8 @@
 
 
 def _check_tracing():
+    import defines
+
     if defines.TRACING_ON:
         return